René Mõttus

Specificity

The Five-Factor Model personality traits tend to be associated with many outcomes (non-personality variables) in a fairly similar manner and the same outcomes often have similar associations with most personality traits. In particular, socially favourable personality trait levels correlate among themselves and with desirable outcomes; therefore, we call this the 'positive-things-go-together' pattern. There are several possible reasons for this pattern. It could reflect veridical and meaningful ways in which people differ from each other, along the lines of general factor of personality or yet more general fitness factors. Alternatively, it could result from complex multivariate causal mechanisms (e.g., the crud factor) or from methodological artifacts (e.g., rating biases, poor questionnaire design). This ambiguity may limit the informativeness of particular personality trait-outcome associations. In order to quantify the level of uniqueness in particular personality trait-outcome associations, over and above the 'positive-things-go-together' pattern, we have put forward the concept of specificity, operationally defined as the probability that an observed trait-outcome association is stronger than the association of any random combination of personality questionnaire items with the outcome. This definition provides a simple specificity metric that can be used as a post hoc tool to evaluate the substantive importance of specific trait-outcome associations.

In order to facilitate carrying out such specificity analyses, we have developed an R-package called 'specificity', which is available at CRAN. Any feedback is welcome (rene.mottus ut ee).

To install the packages in R:
install.packages("specificity")